Problem: What is the greatest common factor of $6$ and $12$ ? Another way to say this is: $\operatorname{gcf}(6, 12) = {?}$
Explanation: The greatest common factor is the largest number that is a factor of both $6$ and $12$ The factors of $6$ are $1$ $2$ $3$ , and $6$ The factors of $12$ are $1$ $2$ $3$ $4$ $6$ , and $12$ Thus, the greatest common factor of $6$ and $12$ is $6$. $\operatorname{gcf}(6, 12) = 6$